T5 was built before they bought BMI for a start
There is space for T5 for T5D, T5E, T5F and maybe T5G, but first it would require the demolishion of T3
Will this be enough for BA's ops (including growth and for agruements sake VS's and EI's LHR ops?)?
Until then once several carriers leave T3 (once T2 opns), I am guessing that BA will consolodate into T3-T5, if not then we coul see BA flights out of T2...
For the longer term (if allowed), there is space for up to 4 addtional runways and with that 1-2 addtional terminal complexs (i.e. routhly the size of T2-T3-T5)